Библиографическое описание:Метрологическое обеспечение проведения испытаний микрополосковых СВЧ-фильтров : научное издание / С. С. Сарвар [и др.]. - Текст : непосредственный // Успехи современной радиоэлектроники. - 2018. - № 12. - С. 100-104. - ISSN 2070-0784, DOI 10.18127/j20700784-201812-20. Перевод заглавия: Metrological assurance of testing microstrip microwave filters
Аннотация:Приведена методика верификации векторного анализатора цепей с произвольным числом измерительных каналов с целью определения основных метрологических характеристик: погрешностей измерений комплексных коэффициентов передачи и отражения. Выполнено построение параметрической модели многопортового векторного анализатора цепей на основе общей 12-параметрической модели. Представлены результаты применения методики для автоматизации проведения испытаний экспериментальных образцов полосно-пропускающих фильтров радиолокационных систем.
Researches and developmental operations on development of the radio electronic equipment intended for use in the microwave range of radio waves is connected with the design of a significant number of the microstrip microwave filters. At the same time, different variants of geometry and structure organization of filters shall be tested and there is a problem of metrological and software support of the carry out testing in the automated or automatic mode. The main parameters of microwave filters are: amplitude and phase frequency responses, the difference of group delay and the signal attenuation level in the stopbands. The experimental filter sample can be represented as a matrix description based on the concept of an equivalent multipolar network with inputs in the form of cross sections of transmission chains. Thus, it is necessary to develop methods for calibrating multi-port devices by generalize the available experience of using known methods and adapt them to multiport VNA. At the same time, a set of new methods and models (methodology) should take into account calibration using either a mechanical set of measures or an electronic calibrator in automatic mode at the probe station or by means of software built into the device. The article presents the technique of the VNA verification with arbitrary number of measuring channels for the purpose of determination the main metrological characteristics: errors of measurements of complex transmission ratios and reflection. In addition, the design of the parametric model of the multi-channel VNA on the basis of the general 12-parametric model is executed. When developing the 12-parameter model of a four-port VNA, it is possible to distinguish four variants for interaction between measurement channels, which, in turn, are subdivided into four basic and additional variants. Calibration and definition of measurement error values for multiport VNA can be represented as a set of separated two-port calibration for VNAs ports in accordance to possible connecting circuits for tested microwave device and VNA. Therefore, for 4-port VNA it is necessary performed two calculation cycles for measurement error definition of basic connection circuits and two determination cycles for influence definition of cross interaction values between measuring channels. Results of using the method in the case of the automation of carry out testing of the experimental samples of the band passing filters for radar systems are provided. Using this method it is possible to determine the parameters of devices with low losses, such as transitions, or the parameters of cable assemblies for various bends to estimate the influence on the error of VNA measurements, or the departure of parameters for distorting adapters according to the VNA model. The developed method is characterized by high accuracy of estimating the measurement error values, in comparison with well-known techniques for estimating VNA parameters, and it is useful for metrological assurance of measurements in microwave technology using probe stations.
